The son of a 27-year L.A. County Sheriff, Poole would "follow in his father's footsteps" and join the LAPD in 1981. He rose quickly, becoming a detective trainee only three years after being sworn in. Before being chosen to work in the Robbery-Homicide division in 1996, he spent over 9 years as a homicide investigator at the South Bureau and Wilshire Division. He served as the primary investigator (taking a case all the way through the trial) on at least 135 homicide cases, and assisted on over 500 more. Noteworthy cases investigated personally by Poole before the Rampart scandal include and the murder of Ennis Cosby, the son of actor/activist/comedian Bill Cosby.[1] He also was one of the officers involved in the investigation that followed the 1997 North Hollywood shootout, just days before the murder of the Notorious B.I.G. Throughout his career up to his involvement in the Rampart scandal, Poole was a highly respected and decorated LAPD detective.

Poole's involvement in the Rampart scandal began less than six months before the murder of the Notorious B.I.G. and a year before Rafael Perez was arrested. His involvement would begin when Poole and his then-partner at Robbery/Homicide, Fred Miller, were assigned to investigate the March 1997 Studio City shooting death of LAPD Officer Kevin Gaines. Gaines was killed in a "road rage" dispute after he brandished a gun at another motorist, which turned out to be undercover officer Lyga.

On March 9, 1997, at around 12:30 a.m., Biggie Smalls, Bad Boy Records CEO Sean Combs, and their entourage left the 11th Annual Soul Train Music Awards after-party, held at the Petersen Automotive Museum, in two GMC Suburbans to return to his hotel after an announcement was made that the party would finish earlier than planned. Biggie traveled in the front passenger seat of the second Suburban alongside his associates, Damion "D-Rock" Butler, Junior M.A.F.I.A. member Lil' Cease and driver, Gregory "G-Money" Young. Combs traveled in the first vehicle with three bodyguards. The two trucks were trailed by a Chevrolet Blazer carrying Bad Boy's director of security.

By 12:45 a.m., the streets were crowded with cars full of people leaving the event. Biggie's truck stopped at a red light 50 yards (46 m) from the museum. While waiting for the light to change, a white Toyota Land Cruiser made a U-turn and cut in-between Biggie's vehicle and the Chevrolet Blazer behind. Simultaneously, a black Chevrolet Impala pulled up alongside Biggie's SUV. The driver of the Impala (an African-American male neatly dressed in a blue suit and bow tie) rolled down his window, drew a 9mm blue-steel pistol and fired several rounds into the GMC Suburban; four bullets hit Biggie in the chest. Biggie was rushed to Cedars-Sinai Medical Center by Combs and the rest of Biggie's entourage, but was pronounced dead by doctors at 1:15 a.m.

After months of investigating and substantial amounts of evidence[citation needed], Poole accused an LAPD officer, Officer David Mack, along with his friend, Amir Muhammad, of being complicit in the murder. Poole had enough evidence that Officer Mack had ties with the CEO of Death Row Records, Marion "Suge" Knight[citation needed] to suspect him and possibly other officers in the murder.[citation needed][2] He had sources that he grew up in the same neighborhood as Knight (Compton), was in the same gang as Knight (the Bloods), was a frequent visitor at Knight's private parties, and wore the same blood red clothes as Knight and the Bloods gang.

Poole eventually sent this information to the then-chief of the Los Angeles Police Department, Bernard C. Parks, who ordered Poole to cease all investigations on Officer David Mack. Poole, in protest of Parks and the LAPD's handling of the case, retired from the department in late 1999[3] after a long and rewarding career. Distraught from being forced into early retirement and the end of the investigation, Poole initially planned on committing suicide, but reconciled in thought of his family and relatives. He would later state that "I almost took my life, but it was my kids that actually saved me".[4] Furthermore, he filed a lawsuit against the LAPD for violating his First Amendment rights by preventing him from going to the public with his information.[5] He has since taken over the investigation of the rapper's slaughter himself after starting his own detective service. Poole was featured in a 2001 interview with VH1 and in the controversial documentary film, Biggie & Tupac, conducted by Nick Broomfield in 2001 and released on VHS and DVD in January 2002.

LAbyrinth: A Detective Investigates the Murders of Tupac Shakur and Notorious B.I.G., the Implication of Death Row Records' Suge Knight, and the Origins of the Los Angeles Police Scandal, Atlantic Monthly Press, ISBN 978-0-87113-838-5.